The present invention relates to a travel support device, a travel support method, and a drive support system that manage adaptation of a plurality of travel modes of a vehicle.
Conventionally, as a vehicle provided with a plurality of travel modes as described above, a hybrid vehicle that uses both an internal combustion engine and a motor as its drive sources is known. The hybrid vehicle has a plurality of travel modes including a first mode (EV mode), in which the state of charge of the battery is not maintained by giving priority to EV travel, which stops the internal combustion engine and travels using only the motor, and a second mode (HV mode), in which the state of charge of the battery is maintained by giving priority to HV travel, which uses both the internal combustion engine and the motor to travel. Further, a travel support device that includes a navigation system and the like installed in the hybrid vehicle calculates a travel route from the current location to a destination based on map information and road traffic information and selects a travel mode to be adapted to each section which is a dividing unit of the travel route. For example, Japanese Laid-Open Patent Publication No. 2009-12605 discloses an example of a controller of a vehicle having such travel support functions.
In the controller of the vehicle disclosed in the above-described publication, travel modes of the individual sections on a travel route are set, with consideration given to the entire energy balance of the travel route so that the remaining charge of the battery, which is a rechargeable battery, becomes zero at the destination. However, prediction may be incorrect depending on factors such as changes in traffic flow, and the remaining charge of the battery may decrease faster than the prediction. In such a case, the travel mode may be changed to a second mode in a first priority section, where travel at the first mode is desired to be given priority. As a result, an uncomfortable sensation may be experienced by the driver.
The above-described problem is generally common to devices and methods that assign travel modes to a vehicle having a plurality of travel modes with a different energy balance.